Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Innovation in spectroscopy could improve greenhouse gas detection

16.05.2013
Detecting greenhouse gases in the atmosphere could soon become far easier with the help of an innovative technique* developed by a team at the National Institute of Standards and Technology (NIST), where scientists have overcome an issue preventing the effective use of lasers to rapidly scan samples.

The team, which recently published its findings in the journal Nature Photonics, says the technique also could work for other jobs that require gas detection, including the search for hidden explosives and monitoring chemical processes in industry and the environment.


Fast, accurate spectroscopy scans of the atmosphere across a wide range of light frequencies could improve the performance of greenhouse gas measurement devices. This artist's conception compares current technology, which functions slowly and unevenly, with the NIST team's improvement, which changes the scanning laser's frequency evenly and more than 1,000 times faster, permitting full-spectrum scans within a few milliseconds.

Credit: Talbott, Gerskovic/NIST

Searching for faint whiffs of an unusual gas mixed in the air is called "trace gas sensing." By far, the most common method is spectroscopy—identifying gas molecules by the unique set of frequencies of light that each absorbs. The telltale pattern of dark lines in a spectrum indicates which gases are present in the mix. Accurately measuring the concentrations of relatively low-concentration gases, however, requires a lot of light, generated by a laser that can be tuned to different colors. Until now, tuning a laser to shine in a wide enough range of colors typically has required a mechanical device to change the frequency, but all the available methods adjust the laser too slowly to obtain meaningful snapshots of the turbulent atmosphere.

"One of the major goals in climate science is to combine a wide variety of high-accuracy atmospheric measurements, including ground-based, aircraft and satellite missions, in order to fully understand the carbon cycle," says the research team's David Long, a scientist in NIST's Chemical Sciences Division. "The technology we've developed is general enough to be applicable for each of these platforms. The high speed of the technique allows for very accurate measurements of atmospheric gases at rates which are faster than atmospheric changes in temperature and pressure due to turbulence."

The team found a solution using electronics that permit fast and discrete changes in frequency. The components—called an electro-optic modulator and an optical resonator—work together to alter the laser so that its light shines in a number of different frequencies, and then to filter these frequencies so that the laser only shines in one color at any given instant. The new method allows a wide range of different frequencies to pass through a gas sample in a few milliseconds or less, with the added benefit of providing a clearer and more accurate resulting spectrum than the previous "slow scan" methods could.

Long says that the Nature Photonics paper details the use of the technique in a controlled laboratory environment using a small sample chamber for ground-based measurements, but that the team has submitted other papers with data indicating the technique also could work at great distances—potentially allowing a scanner to be mounted on a vehicle, an aircraft or a satellite. The team also has applied for a patent on its work, he says.

*G.-W. Truong, K.O. Douglass, S.E. Maxwell, R.D. van Zee, D.F. Plusquellic, J.T. Hodges and D.A. Long. Frequency-agile, rapid scanning spectroscopy. Nature Photonics, DOI: 10.1038/NPHOTON.2013.98, April 28, 2013.

Chad Boutin | EurekAlert!
Further information:
http://www.nist.gov

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>